You need to see a neurologist.
One would not jump to an MRI of the brain. Too much thyroid medicine, diabetes, low magnesium, B vitamin deficiency, other electrolyte imblance, muscle strain and stress, benign fasiculations.....and more All of these need to be ruled out.
MRI would only be based on neuro exam findings.
Parkinsons typically does not start like this.
Certainly, rare causes, such as MD and ALS can easily be ruled out by the correct specialist.
I am a double board certified doctor.
Let me know if you have more questions.
Please do not forget a positive rating.
Thanks for ideas. Should I tell my GP that I have contacted you and ask to get tested on the things you have suggested? I am worried he will think I am a hypochondriac. I have just moved to this area and don't know him very well although he seems attentive. My thyroid and diabetes levels were in the normal range at the last test although he did seem puzzled at the diabetes reading of 6 and gave me the impression I should not be on metformin. I am taking 75mg of thyroxin. What does ALS stand for?